Lauritz p



v Nrrnn raras LAURITZ P. LANDTVED, OF COPENHAGEN, DENMARK.

HYDRAULIC PRESAS.

SPECIFICATION forming part of Letterslatent No. 607,442, dated July `19, 1898.

Application filed January 10, 1898. 'Serial No. 666,215. (No modelo To all whom it may concern: v

Be it known that I, LAURITZ P. LANDTVED, of Copenhagen, Denmark, have invented certain new and. useful Improvements in I'Iydraulic Presses; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawing, and to letters of reference marked thereon, which forms a part of this specification.

This invention has for its object certain improvements in hydraulic presses-as, for instance, in presses for shaping sheet metal or making sheet-metal ware or utensilsapplicable also to other purposes. K

In the accompanying drawing I have shown my improved hydraulic press by a vertical` sectional elevation, in which a in dicates the cylinder, the interior diameter of which Varies, and is iitted` with two pistons o and c, arranged in tandem, the former, bfworking in the upper portion of greatest diameter of the cylinder and the piston' ein the lower portion of least diameter of said cylinder, said pistons being so arranged as to leave a fluidspace a between them and a like space'b below the smaller piston.

The piston l) carries the support f for the sheet metal to be shaped.

The piston c has secured thereto a rod d, that passes fluid-tight through the piston l) and carries at its upper end the male die c.

The piston b has laterally-projecting perforated ears a2, through which pass the guiderods t', that s'erveA to guide the same in its reciprocating movements, said rods having their upper and lower ends screw-threaded for the reception of nuts 7c and providedwith an abutment iiange or c'ollar 7a2, that seats upon perforated ears or projections on the cylinder a, through the perforations of which the rods pass and are secured by means of said nuts 7c, At their upper end the rods' carry a suitable crest-head 47a, secured thereto vby means of nuts 7u', said cross-head carrying the female die g ink a well-known manner.

On one side of the cylinder a is arranged a distribution-valve chest q, whose branch y is connected with a source of fluid-supply under pressure, as a force-pump,while its branch t is connected with a receiving-chamber r. From the valve-chest q lead two ducts u and c to the spacco below the smaller pistbnc and to the space a between said piston and the larger piston b, respectively. The duct o is in communication with the valve-chest q through a port controlled by a valve m, and duct a communicates with said valve-chest through a port controlled by ya valve n and withthe receiving-chamber fr through the duct t and a suitable port controlled by a valve o. The ductcis, furthermore, in communication with a duct 8,-leading to receiving-chamber 11 through a port controlled by a pressure-regulatin g Valve 0o, connected with a weighted lever L, the weight Z of which is adjustable on its lever, which is fulcrumed to a suitable standard rising from the duct o in the valve-chest.

The d uct s, forming a by-pass from the d uct c through the safety or regulating valve discharges into the chamber yr, and the pressure with which the work is held between the support fand die g can be regulated by suitably positioning thevweight on the lever L. This valve also allows the escape of the displaced water due to the rise of the cylinder c.

The stems of the valves m, n, and o are pivoted to a two-armed lever Z, fulcrumed at Z to a bracket on the Valve-chest.

The operation of the press is as follows, the parts being shown in the drawing in their relative positions for operation: A sheet of metal p being placed upon the annular support f and the force-pump started the water will flow through the open port m to the space a between the pistons b and c, and as the superiicial area of the face of piston b acted upon by the water is greater than that of the proximate face of piston c the former or larger piston will be caused to ascend, carrying with it the smaller piston c. When the said piston l) has carried the plate p nearly to the female die g,the valve-shifting lever l is moved from its extreme position to the right, as shown in the drawing, to its extreme position to the left of its mean vertical position, whereby the Valves m and o are moved to close their respective ports, while the valve n is moved to open its port, thereby admitting water under pressure to the chamber b below piston c, whereby the latter is caused IOO to move upward, the pressure being likewise transmitted to the body of Water between the pistons, thereby causing piston l) to complete its upward movement and hold the plate 19 to the female die g, while the piston c completes its movement to shape said plate by the action thereon of the male die e and the cooperation therewith of said female die g. Should the male die stick fast in the matrice g from any cause, the valve-shifting lever Z is moved to the first position to the right, thereby causing the pressure of the water to be exerted upon piston c in a downward direction, because piston Z) is still in contact with the female die and is thereby held against upward motion, so that the said piston c will be caused to move out of said die. After the described operation the valve-shifting lever is moved to its third or normal position-t'. e., its mean perpendicular position-thereby moving all the valves to uncover their respective ports and allowing the pump to work without actuating the pistons, both of which drop into their normal positions.

It will of course be understood that the suction-pipe (not shown) is connected with the reservoir i' at r' and the force-pipe of said pump with the inlet branch Y of the valvecasing, as above stated.

Having thus described myinvcntion, what I claim as new therein, and desire to secure by Letters Patent, is

l. In a hydraulic press, the combination with a stationary die, t-he press-cylinder, two pistons of unequal diameter arranged in tandem, the piston of greater diameter adapted to support the material operated upon, and the cooperating die secured to the smaller piston; of means for admitting a ilnid under pressure at will between the two pistons and below the smaller piston respectively, for the purpose set forth.

2. In a hydraulic press, the combination with a stationary die, the press-cylinder, and two pistons of unequal diameter arranged in tandem, the piston of greater diameteradapted to support the material operated upon,and the cooperating die secured to the smaller pisvalve-chest for the ducts leading to the cyl,

inder above and below the smaller piston and open the port connectin g the last-named duct with the receiving-chamber when the leveris shifted in one direction, and to cnt oit the communication between the cylinder and receiving-cha1nber and the duet leading to said cylinder above the smaller piston and to open the port leading from the valvechest to the cylinder below the smaller piston when said lever is shifted in a reverse direct-ion, for the purpose set forth.

3. In a hydraulic press, the combination with the cylinder, its two pistons of unequal diameter arranged in tandem, a valved duct leading to the cylinder between its pistons, and a receiving-chamber, of a by-path connectin g the receiving-chamber with the aforesaid duct, and a pressure-regulating valve in said by-path, for the purpose set forth.

4. In a hydraulic press, the combination with the cylinder, its two pistons of unequal diameter arranged in tandem, a valved duct leading to the cylinder between its pistons, and a receiving-chamber; of a by-path connecting the receiving-cl1amber with the aforesaid duct, and an adjustable pressure-regulating valve in said by-path, for the purpose set forth.

In testimony that I claim the foregoing as invention I have signed my name in presence fof two subscribing witnesses.

LAURITZ I). LANDTVED.

lVitnesses:

HANS PETER NIKoLEv JANSEN, JULEs BLOW. 

